Jet aircraft typically include one or more engines that may generate high levels of noise. For example, a fan case within a housing secured to a wing of an aircraft typically generates noise. Often, engine housings include one or more sound dampening structures that are used to absorb at least a portion of the noise generated by components of an engine. As an example, an acoustic inlet barrel may be positioned at or proximate to an inlet of the engine housing upstream from a fan case. Certain known acoustic inlet barrels are formed of composite materials, such as carbon-reinforced plastics, that are sandwiched around an acoustic core.
A composite structure may include panels that are fabricated with honeycomb or foam cores. A honeycomb core is structurally efficient, but may be expensive to produce. In particular, a honeycomb core may be formed through various processes that are labor and time intensive. In general, the core is cut, bonded, milled to contour, and formed. Typically, in order to form a core of a particular shape, a support structure is first formed. Portions that form the acoustic core are then layered over the support structure, which provides the particular shape to the core. After the core is formed, the support structure is typically discarded, as it forms no part of the actual core.
As can be appreciated, the process of first forming a support structure adds time and cost to the manufacturing process. Also, adding a septum to core cells increases costs and complexity of the composite structure. Further, using a support structure to form a core generates waste, as the support structure itself does not form part of the core.